Simon Rice, the group manager for technology at the UK's Information Commissioner's Office (ICO), said, "Today's results show that many app developers are still failing to provide this information in a way that is clear and understandable to the average consumer.

"The ICO and the other GPEN members will be writing to those developers where there is clear room for improvement.

"We will also be publishing guidance to explain the steps people can take to help protect their information when using mobile apps."

Dr Stephen Murdoch, a researcher at University College London, believes that the use of third-party advertising platforms should take some of the blame. "Often privacy leaks from mobile apps don't come from the app itself, but from the advertisements which are added.

"Quite frequently the people who are writing the application don't understand themselves what they advertisement code is doing.